Safety pilot



Patented JunerZ, 1942 George C. Bergtholdt, Jr., Tulsa, Okla., assignorto Webster Engineering Company, Tulsa, Okla., c a corporation ofDelaware Y A Appli-marien september 2r, 1939, serial No. 29aml 1 claim.(C1. 15s-117.1)

Burner control systemswhich depend on the of a pilot burner are wellknown in the art. In

this connection see patent to Knowles 1,809,280.Y However, heretoforethe application of such' aV control system to burners already installedand more particularly to burners that are installed in the wall of afurnace rebox, such as a steam boiler firebox, has not been an easyAmatter, and in any event has been a time consuming operation. Thepresent inventiontherefore has for its object to provide a unit whichshall makevit a relatively simple matter to install-a control system forburnersalready in place.

In the accompanying drawing wherein` the preferred form of the inventionis shown,-

Fig. 1 showshow the unit Vof the present inventicn will ordinarily beinstalled in a furnace wall having a main burner positioned in saidwall, the unit being shown in side elevation and passage of an electriccurrent through the flame i Y through an opening in the end wall 23thereof from a source of supply of combustible mixture. The tube islsecured to theY Wall 23 by a screw 24 which extends through a securinglug 25 carried by the tube. A spacer bracket 26 on the tube adjacent theother end of the casing 20` serves to hold the pilot burner and tubeagainst Vlateral displacement. The end wall 23 is detachably secured tothe end of the casing by screws 21 and 28. A sight glass 29` carried bysaid end'wall is adapted to be moved to one side to permit the insertionof a torch into the casing for initially lighting the pilot burner. Aslidable damper 30 on top of thecasing admits sec- Y ondary air to thepilot burner.

The means for shutting off the supply of fuel Y to the burner block I0comprises anfL-shape curparts of the main burner and furnace wall beingshown in vertical section; p

Fig. 2 is a plan view of the unit itself withV parts broken away andnsection to more clearly show the relationship of the parts;

Fig. 3 is an end elevation on line'3-3 of Fig. l, and I I. Fig. 4 is anend elevation on line 4 4 'of Fig. 2 with parts in section.

In the drawing, there is shown a burner positioned in the wall H of asteam boiler rebox Whose'floor is indicated at I2. 'I'he burner may TIObe of preferred type and is here shown as comf prising a block .I0`having rows cfring ports I3 to which fuel gas is delivered by gasnozzles I4 which extend from a manifold I5 at the endof a fuel supplypipe I3 -provid'edwith a gas Valve I'I, adapted to be operated by anelectric motor I 3. dicated at I9.

The unit of the present invention comprises a ducttype casingZadapted toextend into the furnace wall I I to apointbelow the burner block IIJ asclearly shown in Fig. l. In the case of an already installed burner theinstallation of the casing is readily accomplished by removing bricksfrom the wall II. In installing the Acasing it is preferred to place abrick barrier 20' a short distance in advance of therebox end of thecasing to shield it and the parts therein from radiant heatfrom thefirebox, it being noted that said end is not closed.

` The pilot burner for lighting the main burner I0 is indicated at ZIand is supported by a gas supply tube 22 which extends into the casingThe usual air control mechanism is in-V rent-conducting member whoseshort leg or arm is indicated at 3l and whose' long leg or arm isindicated at 32. The long leg-32 extendsrfrom and is supported by a head33 which is detachably secured to the end wall 23 of the'casing 20 bymeans here shown as including a bracket 3l! adapted to be secured tosaid Wallby the wall securing screws 28 and the short leg 3l extendsupwardly at an'angle into the path of flame from! L the pilot burner 2l.rIfhe primary purpose of detachably securing the head 33 to said endwall is to permit thesaid L-shape member to be withdrawn from the casingfor inspection and repairs and, of course, also to facilitate itsinstallation after the pilot burner is in place. To remove the L-shapemember from the casing 2B after the head 33 hasbeen released from theend wall 23 it is merely necessary to pull the head awayV from said wallsufficiently far to permit the short arm 3| to clear the pilot burnerand then to turn the-head to dispose said short arm 3I in prone positionafter which it may be readily drawn through the casing as will now bereadily understood. In this connections note that the :pilot burner vispositioned far enoughY in advVance of the burner block Ill to providel aclearance space which permits the arm 3l to be turned to prone positionas said. As shown in Fig. 2 the arm 3l preferably comprises an angledrod which is screwed into the end of the long` leg 32 thereby making ita simple matter to replace the flamerodSIas conditions require.

The Helectrical means which cooperates with thersaid L-shapecurrent-conducting member to shut off the, supply of fuel to the burnerblock I0 incase the pilot flame goes out is diagrammatically indicatedat 35.

What I claim is:

In combination, an upright furnace wall, a burner comprising a portedblock positioned in said wall to re into said furnace, a relatively longwide duct positioned in said wall at one side of said burner with theforward end of the duct positioned under said block, a gas burning pilotfor igniting the fuel issuing from said block and positioned in advanceof the forward end of said duct and being passable through the duct, andmeans for shutting off the supply of fuel to the burnerin case the pilotis ineffective to ignite the fuel issuing from said block, said shut-offmeans comprising an L-shape current conductlng member whose short arm isnormally positioned in advance of the front end of said duct to extendupwardly at an angle across the path of flame from said pilot and whoselong arm extends rearwardly into said duct, said member as a whole beingpassable rearwardly through the duct when the short arm thereof ishorizonl0 tally disposed.

GEORGE C. BERGTHOLDT, JR.

